/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.iotdb.tsfile.write.schema;

import org.apache.iotdb.tsfile.common.conf.TSFileDescriptor;
import org.apache.iotdb.tsfile.encoding.encoder.Encoder;
import org.apache.iotdb.tsfile.encoding.encoder.TSEncodingBuilder;
import org.apache.iotdb.tsfile.file.metadata.enums.CompressionType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
import org.apache.iotdb.tsfile.utils.ReadWriteIOUtils;
import org.apache.iotdb.tsfile.utils.StringContainer;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.nio.ByteBuffer;
import java.util.*;

public class VectorMeasurementSchema
        implements IMeasurementSchema, Comparable<VectorMeasurementSchema>, Serializable {

    private String deviceId;
    private Map<String, Integer> measurementsToIndexMap;
    private byte[] types;
    private byte[] encodings;
    private TSEncodingBuilder[] encodingConverters;
    private byte compressor;

    public VectorMeasurementSchema() {
    }

    public VectorMeasurementSchema(
            String deviceId,
            String[] subMeasurements,
            TSDataType[] types,
            TSEncoding[] encodings,
            CompressionType compressionType) {
        this.deviceId = deviceId;
        this.measurementsToIndexMap = new HashMap<>();
        for (int i = 0; i < subMeasurements.length; i++) {
            measurementsToIndexMap.put(subMeasurements[i], i);
        }
        byte[] typesInByte = new byte[types.length];
        for (int i = 0; i < types.length; i++) {
            typesInByte[i] = types[i].serialize();
        }
        this.types = typesInByte;

        byte[] encodingsInByte = new byte[encodings.length];
        for (int i = 0; i < encodings.length; i++) {
            encodingsInByte[i] = encodings[i].serialize();
        }
        this.encodings = encodingsInByte;
        this.encodingConverters = new TSEncodingBuilder[subMeasurements.length];
        this.compressor = compressionType.serialize();
    }

    public VectorMeasurementSchema(String deviceId, String[] subMeasurements, TSDataType[] types) {
        this.deviceId = deviceId;
        this.measurementsToIndexMap = new HashMap<>();
        for (int i = 0; i < subMeasurements.length; i++) {
            measurementsToIndexMap.put(subMeasurements[i], i);
        }
        this.types = new byte[types.length];
        for (int i = 0; i < types.length; i++) {
            this.types[i] = types[i].serialize();
        }

        this.encodings = new byte[types.length];
        for (int i = 0; i < types.length; i++) {
            this.encodings[i] =
                    TSEncoding.valueOf(TSFileDescriptor.getInstance().getConfig().getValueEncoder())
                            .serialize();
        }
        this.encodingConverters = new TSEncodingBuilder[subMeasurements.length];
        this.compressor = TSFileDescriptor.getInstance().getConfig().getCompressor().serialize();
    }

    public VectorMeasurementSchema(
            String deviceId, String[] subMeasurements, TSDataType[] types, TSEncoding[] encodings) {
        this(
                deviceId,
                subMeasurements,
                types,
                encodings,
                TSFileDescriptor.getInstance().getConfig().getCompressor());
    }

    @Override
    public String getMeasurementId() {
        return deviceId;
    }

    @Override
    public CompressionType getCompressor() {
        return CompressionType.deserialize(compressor);
    }

    @Override
    public TSEncoding getEncodingType() {
        throw new UnsupportedOperationException("unsupported method for VectorMeasurementSchema");
    }

    @Override
    public TSDataType getType() {
        return TSDataType.VECTOR;
    }

    @Override
    public byte getTypeInByte() {
        return ((byte) 6);
    }

    @Override
    public void setType(TSDataType dataType) {
        throw new UnsupportedOperationException("unsupported method for VectorMeasurementSchema");
    }

    @Override
    public TSEncoding getTimeTSEncoding() {
        return TSEncoding.valueOf(TSFileDescriptor.getInstance().getConfig().getTimeEncoder());
    }

    @Override
    public Encoder getTimeEncoder() {
        TSEncoding timeEncoding =
                TSEncoding.valueOf(TSFileDescriptor.getInstance().getConfig().getTimeEncoder());
        TSDataType timeType = TSFileDescriptor.getInstance().getConfig().getTimeSeriesDataType();
        return TSEncodingBuilder.getEncodingBuilder(timeEncoding).getEncoder(timeType);
    }

    @Override
    public Encoder getValueEncoder() {
        throw new UnsupportedOperationException("unsupported method for VectorMeasurementSchema");
    }

    @Override
    public Map<String, String> getProps() {
        throw new UnsupportedOperationException("unsupported method for VectorMeasurementSchema");
    }

    @Override
    public List<String> getSubMeasurementsList() {
        String[] measurements = new String[measurementsToIndexMap.size()];
        for (Map.Entry<String, Integer> entry : measurementsToIndexMap.entrySet()) {
            measurements[entry.getValue()] = entry.getKey();
        }
        return Arrays.asList(measurements);
    }

    @Override
    public List<TSDataType> getSubMeasurementsTSDataTypeList() {
        List<TSDataType> dataTypeList = new ArrayList<>();
        for (byte dataType : types) {
            dataTypeList.add(TSDataType.deserialize(dataType));
        }
        return dataTypeList;
    }

    @Override
    public List<TSEncoding> getSubMeasurementsTSEncodingList() {
        List<TSEncoding> encodingList = new ArrayList<>();
        for (byte encoding : encodings) {
            encodingList.add(TSEncoding.deserialize(encoding));
        }
        return encodingList;
    }

    @Override
    public List<Encoder> getSubMeasurementsEncoderList() {
        List<Encoder> encoderList = new ArrayList<>();
        for (int i = 0; i < encodings.length; i++) {
            TSEncoding encoding = TSEncoding.deserialize(encodings[i]);
            // it is ok even if encodingConverter is constructed two instances for concurrent scenario
            if (encodingConverters[i] == null) {
                // initialize TSEncoding. e.g. set max error for PLA and SDT
                encodingConverters[i] = TSEncodingBuilder.getEncodingBuilder(encoding);
                encodingConverters[i].initFromProps(null);
            }
            encoderList.add(encodingConverters[i].getEncoder(TSDataType.deserialize(types[i])));
        }
        return encoderList;
    }

    @Override
    public int getSubMeasurementIndex(String subMeasurement) {
        return measurementsToIndexMap.getOrDefault(subMeasurement, -1);
    }

    @Override
    public int getSubMeasurementsCount() {
        return measurementsToIndexMap.size();
    }

    @Override
    public boolean containsSubMeasurement(String subMeasurement) {
        return measurementsToIndexMap.containsKey(subMeasurement);
    }

    public void addMeasurement(String measurementId, TSDataType dataType, TSEncoding encoding) {
        measurementsToIndexMap.put(measurementId, measurementsToIndexMap.size());
        byte[] typesInByte = new byte[measurementsToIndexMap.size()];
        if (measurementsToIndexMap.size() - 1 >= 0) {
            System.arraycopy(types, 0, typesInByte, 0, measurementsToIndexMap.size() - 1);
        }
        typesInByte[typesInByte.length - 1] = dataType.serialize();
        this.types = typesInByte;
        byte[] encodingsInByte = new byte[measurementsToIndexMap.size()];
        if (measurementsToIndexMap.size() - 1 >= 0) {
            System.arraycopy(encodings, 0, encodingsInByte, 0, measurementsToIndexMap.size() - 1);
        }
        encodingsInByte[encodingsInByte.length - 1] = encoding.serialize();
        this.encodings = encodingsInByte;
        this.encodingConverters = new TSEncodingBuilder[measurementsToIndexMap.size()];
    }

    @Override
    public int serializedSize() {
        int byteLen = 0;
        byteLen += ReadWriteIOUtils.sizeToWrite(deviceId);
        byteLen += Integer.BYTES;
        for (Map.Entry<String, Integer> entry : measurementsToIndexMap.entrySet()) {
            byteLen += ReadWriteIOUtils.sizeToWrite(entry.getKey());
            byteLen += Integer.BYTES;
        }
        byteLen += (types.length + encodings.length + 1) * Byte.BYTES;
        return byteLen;
    }

    @Override
    public int serializeTo(ByteBuffer buffer) {
        int byteLen = 0;
        byteLen += ReadWriteIOUtils.write(deviceId, buffer);
        byteLen += ReadWriteIOUtils.write(measurementsToIndexMap.size(), buffer);

        for (Map.Entry<String, Integer> entry : measurementsToIndexMap.entrySet()) {
            byteLen += ReadWriteIOUtils.write(entry.getKey(), buffer);
            byteLen += ReadWriteIOUtils.write(entry.getValue(), buffer);
        }
        for (byte type : types) {
            byteLen += ReadWriteIOUtils.write(type, buffer);
        }
        for (byte encoding : encodings) {
            byteLen += ReadWriteIOUtils.write(encoding, buffer);
        }
        byteLen += ReadWriteIOUtils.write(compressor, buffer);

        return byteLen;
    }

    @Override
    public int serializeTo(OutputStream outputStream) throws IOException {
        int byteLen = 0;
        byteLen += ReadWriteIOUtils.write(deviceId, outputStream);
        byteLen += ReadWriteIOUtils.write(measurementsToIndexMap.size(), outputStream);

        for (Map.Entry<String, Integer> entry : measurementsToIndexMap.entrySet()) {
            byteLen += ReadWriteIOUtils.write(entry.getKey(), outputStream);
            byteLen += ReadWriteIOUtils.write(entry.getValue(), outputStream);
        }
        for (byte type : types) {
            byteLen += ReadWriteIOUtils.write(type, outputStream);
        }
        for (byte encoding : encodings) {
            byteLen += ReadWriteIOUtils.write(encoding, outputStream);
        }
        byteLen += ReadWriteIOUtils.write(compressor, outputStream);

        return byteLen;
    }

    @Override
    public int partialSerializeTo(OutputStream outputStream) throws IOException {
        ReadWriteIOUtils.write((byte) 1, outputStream);
        return 1 + serializeTo(outputStream);
    }

    @Override
    public int partialSerializeTo(ByteBuffer buffer) {
        ReadWriteIOUtils.write((byte) 1, buffer);
        return 1 + serializeTo(buffer);
    }

    public static VectorMeasurementSchema partialDeserializeFrom(ByteBuffer buffer) {
        return deserializeFrom(buffer);
    }

    public static VectorMeasurementSchema deserializeFrom(InputStream inputStream)
            throws IOException {
        VectorMeasurementSchema vectorMeasurementSchema = new VectorMeasurementSchema();
        vectorMeasurementSchema.deviceId = ReadWriteIOUtils.readString(inputStream);

        int measurementSize = ReadWriteIOUtils.readInt(inputStream);
        Map<String, Integer> measurementsToIndexMap = new HashMap<>();
        for (int i = 0; i < measurementSize; i++) {
            measurementsToIndexMap.put(
                    ReadWriteIOUtils.readString(inputStream), ReadWriteIOUtils.readInt(inputStream));
        }
        vectorMeasurementSchema.measurementsToIndexMap = measurementsToIndexMap;

        byte[] types = new byte[measurementSize];
        for (int i = 0; i < measurementSize; i++) {
            types[i] = ReadWriteIOUtils.readByte(inputStream);
        }
        vectorMeasurementSchema.types = types;

        byte[] encodings = new byte[measurementSize];
        for (int i = 0; i < measurementSize; i++) {
            encodings[i] = ReadWriteIOUtils.readByte(inputStream);
        }
        vectorMeasurementSchema.encodings = encodings;

        vectorMeasurementSchema.compressor = ReadWriteIOUtils.readByte(inputStream);
        return vectorMeasurementSchema;
    }

    public static VectorMeasurementSchema deserializeFrom(ByteBuffer buffer) {
        VectorMeasurementSchema vectorMeasurementSchema = new VectorMeasurementSchema();
        vectorMeasurementSchema.deviceId = ReadWriteIOUtils.readString(buffer);
        int measurementSize = ReadWriteIOUtils.readInt(buffer);
        Map<String, Integer> measurementsToIndexMap = new HashMap<>();
        for (int i = 0; i < measurementSize; i++) {
            measurementsToIndexMap.put(
                    ReadWriteIOUtils.readString(buffer), ReadWriteIOUtils.readInt(buffer));
        }
        vectorMeasurementSchema.measurementsToIndexMap = measurementsToIndexMap;

        byte[] types = new byte[measurementSize];
        for (int i = 0; i < measurementSize; i++) {
            types[i] = ReadWriteIOUtils.readByte(buffer);
        }
        vectorMeasurementSchema.types = types;

        byte[] encodings = new byte[measurementSize];
        for (int i = 0; i < measurementSize; i++) {
            encodings[i] = ReadWriteIOUtils.readByte(buffer);
        }
        vectorMeasurementSchema.encodings = encodings;

        vectorMeasurementSchema.compressor = ReadWriteIOUtils.readByte(buffer);
        return vectorMeasurementSchema;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        VectorMeasurementSchema that = (VectorMeasurementSchema) o;
        return Arrays.equals(types, that.types)
                && Arrays.equals(encodings, that.encodings)
                && Objects.equals(deviceId, that.deviceId)
                && Objects.equals(compressor, that.compressor);
    }

    @Override
    public int hashCode() {
        return Objects.hash(deviceId, types, encodings, compressor);
    }

    /**
     * compare by vector name
     */
    @Override
    public int compareTo(VectorMeasurementSchema o) {
        if (equals(o)) {
            return 0;
        } else {
            return this.deviceId.compareTo(o.deviceId);
        }
    }

    @Override
    public String toString() {
        StringContainer sc = new StringContainer("");
        sc.addTail(deviceId, ",");
        // string is not in real order
        for (Map.Entry<String, Integer> entry : measurementsToIndexMap.entrySet()) {
            sc.addTail(
                    "[",
                    entry.getKey(),
                    ",",
                    TSDataType.deserialize(types[entry.getValue()]).toString(),
                    ",",
                    TSEncoding.deserialize(encodings[entry.getValue()]).toString());
            sc.addTail("],");
        }
        sc.addTail(CompressionType.deserialize(compressor).toString());
        return sc.toString();
    }
}
